Align JV, the team made up of Bouygues, Sir Robert McAlpine and VolkerFitzpatrick, has cast the first of 56 concrete piers supporting the Colne Valley Viaduct, set to become the UK’s longest railway bridge, for HS2.
The viaduct will run for 3.4km to cross a series of lakes on the outskirts of London. The 6m-tall pier, weighing 370 tonnes, was cast using specially designed formwork which was removed after four days.
Each pier is designed to support the full weight of the deck above and rests on a set of concrete piles going up to 55m into the ground.
Construction will involve 292 piles and 56 pile caps across the whole length of the viaduct. The main deck of the viaduct will be built in 1,000 separate segments at a temporary factory nearby before being assembled from north to south, starting next year.
The team has also completed the construction of the first of four jetties across the lakes to get equipment into position to support the construction, thereby taking construction vehicles off local roads. Where the viaduct crosses the lake, the piles will be bored directly into the lakebed, using a cofferdam to hold back the water while the pier is constructed.
HS2 Ltd’s project client, David Emms, said: “The Colne Valley Viaduct will be one of HS2’s most iconic structures and it’s great to see how much has been achieved already. I’d like to thank the whole team for the huge amount of work they’ve done to get us to this point.”
Align’s project director, Daniel Altier, added: “I have no doubt that the viaduct will become one, if not the most striking element of HS2 phase one once complete. The way it will be constructed is going to be equally fascinating for engineers young and old.
“The sections for the deck will be fabricated at our main construction site to the west of London just inside the M25, and using a huge launching girder, the deck will be formed from north to south, along the line of the route, thereby keeping unnecessary construction traffic off the roads.
“I would like to thank the whole team, including our supply chain partners, who have worked very hard to enable us to meet this important milestone in the viaduct’s construction.”
